This video comes from ISSTIP (International Society for the Study of Tension in Performance), and organization which was founded by one of my former teachers, Carola Grindea, and I’m happy to say that this is exactly how I instruct my students in how to lay their hands at the piano. Over the years I’ve gotten away from teaching the students to play with curved fingers…it seemed to cause too much tension. The pad of the fingertip is the most sensitive and that’s what we use to produce tone color. Playing on the bony tip seems to only produce a percussive and harsh tone. Be sure to check out the forums at ISSTIP.